Field of the Invention
[0001] The present invention relates to particles comprising mononuclear or multinuclear
molecular complex particles (or molecular complex assembly particles) comprising at
least one bis-R1,R2-dithiocarbamate-metal complex and at least one ligand. The ligand
is typically a water-soluble pharmaceutically acceptable excipient substance: a polymer
or a detergent. The particles are useful for medical applications, including cancer
treatment and diagnostics. A process for producing such particles is disclosed.
Background Art
[0002] R1,R2-dithiocarbamates (DTC) are strong metal ion chelators known in the literature.
Once DTC reacts with metal form new chemical entity - compound (dithiocarbamate metal
chelate). Some of these compounds display anticancer activity in cellular systems
employing various cancer cell models. However, the compounds with proposed antitumor
activity are not water soluble, which makes it particularly difficult to administer
such complex to patients; also the compounds show low preferential toxicity towards
cancer cells and thus nearly narrow therapeutic index. Both limitations can be overcome
by the present invention.
[0003] Dithiocarbamates (DTC), particularly in chelate complex with various bivalent metals,
exhibit promising anticancer activity in various preclinical models. Metal chelating
properties of DTC's are known for a long time, as well as their antitumor activity.
Several patent documents have covered the use of dithiocarbamate complexes with heavy
metals, especially with copper, zinc, gold or silver, as a treatment strategy for
various malignancies (see e.g.
US20030229064,
US20050096304). However, none of these patent documents has been translated to practical use in
humans so far. Apparently, the main obstacle for the use of dithiocarbamate-metal
compounds in the clinical routine are unfavourable pharmacologic properties, namely
stability and water-based formulation capabilities. For instance, for the most promising
anticancer compound which is bis(diethyldithiocarbamate)copper(II) (or copper bis(diethyldithiocarbamate)),
the solubility constant in water is only in the range of nanograms per litre, which
is insufficient to deliver therapeutic doses in patients.
[0004] Formulation of bis-R1,R2-dithiocarbamate metal complexes in albumin solution was
mentioned in
Skrott Z. et al.: Nature, (2017) 552(7684). However, the use of proteins in the formulation involves several disadvantages,
technical as well as hygienic, toxicology and ethical issues. Immunoreactivity issues
may occur, and during testing in animal models, different types of proteins need to
be used. The stability of formulations comprising proteins may be rather low, and
the formulations are prone to denaturation due to low or high pH values or due to
higher temperatures, or prone to decomposition by action of proteases. Only few proteins
are authorized for pharmaceutical use. Furthermore, only few proteins are commercially
available on a large scale, and they are rather costly due to the costly production
and/or purification.
[0005] The present invention thus aims at providing bioavailable particles comprising bis-R1,R2-dithiocarbamate
metal complex, which would be stable, economical, versatile, and would not involve
ethical, hygienic, toxicology and immunoreactivity issues.
Summary of the Invention
[0006] Object of the present invention is a particulate form of dithiocarbamate-metal complexes
with ligands in the form of molecular complex assembly particles. The ligands are
typically water-soluble polymers and/or detergents such as cholate derivatives.
[0007] The term "water-soluble" refers to substances having the water-solubility (i.e.,
saturated aqueous solution concentration) of at least 0.001 % w/w (i.e., 0,01 ‰ w/w),
preferably at least 0.01 % w/w or at least 0.1 % w/w or at least 1 % w/w, in deionized
water.
[0008] Water-soluble polymers are substances containing monomeric units, typically repeating
monomeric units, and having water solubility of at least 0.001 % w/w, preferably at
least 0.01 % w/w or at least 0.1 % w/w, in deionized water.
[0009] Water-soluble detergents are surface active agents having water solubility of at
least 0.001 % w/w, preferably at least 0.01 % w/w or at least 0.1 % w/w, in deionized
water.
[0010] Preferred polymers and/or detergents are those that are acceptable for use as pharmaceutical
excipients. Such ligands have a low or no toxicity and are tested and registered for
use in pharmaceutical formulations, such as therapeutical or diagnostic preparations.
[0011] The particles of the present invention are suitable for use as anticancer drugs or
as diagnostic agents.
[0012] The particle of the present invention comprises or consists of dithiocarbamate-metal
complex and at least one ligand, and the particle is in the form of a molecular complex
assembly typically involving multiple molecules of dithiocarbamate-metal complex and
multiple ligand molecules of one or several types. The particle preferably has the
size in the range of 1-2000 nm. The particulate form is preferably substantially free
of organic solvents.
[0013] Preferably, the complex particle comprises or consists of dithiocarbamate-copper
complex and at least one ligand, or more particularly of diethyldithiocarbamate-copper
complex and at least one ligand, in the form of a molecular complex assembly typically
involving multiple molecules of the dithiocarbamate-copper complex and multiple ligand
molecules of one or several types. The particle preferably has the size in the range
of 1-2000 nm. The particulate form is preferably substantially free of organic solvents.
[0014] According to the present invention, the complex particle is prepared by combining
at least one ligand with a first component selected from a dithiocarbamate or a metal
salt in an aqueous solvent, and simultaneously or subsequently adding a second component
selected from a dithiocarbamate or a metal salt, whereas if the first component is
a dithiocarbamate, then the second component is a metal salt; and if the first component
is a metal salt, then the second component is a dithiocarbamate.
[0015] Within the framework of the present invention, it was discovered that when the simultaneous
or sequential addition of the reagents is carried out as described herein, then after
the addition of the second component, the ligand has a considerable capacity to bind
to the dithiocarbamate-metal compound that is rapidly formed in the solution and spontaneously
assemble into higher molecular complex assemblies, typically of the size within the
range 1-2000 nm, thus forming a bioavailable dispersion. In this form the molecules
of dithiocarbamate-copper complex are uniformly distributed within the assembly, maintain
their original chemical properties and exhibit a substantially improved biological
activity, both
in vitro and
in vivo, thus enabling the therapeutic or diagnostic use of an otherwise water-insoluble
compound, including the use in cancer treatment and tumour imaging.
[0016] The process of complex particles preparation can be performed in a very short time
(below 1 minute), in a single reaction vessel without the need for organic solvents
and which allows either immediate or sustained parenteral, topical or per-oral administration.
[0017] The present invention further includes a kit of parts comprising a dithiocarbamate,
a metal salt, at least one ligand, a sterile aqueous solvent wherein the aqueous solvent
is preferably water or water-based buffer, and a container for combining the at least
one ligand, the dithiocarbamate and the metal salt in the aqueous solvent under sterile
conditions. The components of the kit may be provided in separate containers within
the kit.
[0018] The particles of the present invention have a number of advantages. The non-human
origin of the polymers and detergents removes ethical, safety and immunotoxicity issues
which are connected with blood protein ligands. The particles are stable, do not undergo
denaturation due to low or high pH values or in high temperatures, they are resistant
to enzymes such as proteases. The ligands are commercially available on industrial
scale and non-toxic. The possibility to use various polymers and/or detergents allows
fine-tuning the final desired physico-chemical properties of the resulting particles.
Detailed Description of the Invention
[0019] In the present invention, "molecular complex assembly particles" mean multinuclear
molecular complex particles, wherein typically one particle contains one or several
molecules of bis-dithiocarbamate metal complex and one or several molecules of the
ligand. The molecular complex corresponds to a complex formed by at least two molecules
which are typically bound together by non-covalent bonds.
[0020] The wording "particular form" means "particles".
[0021] In the present invention, "metal" means a metal selected from transition metals (or
d-metals) and metals of the IIIA and IVA groups of the periodic table. Preferably,
metals are transition metals. More preferably, the metal is selected from copper,
zinc, cadmium, mercury. Most preferably, the metal is copper. All advantages of the
present invention are most strongly pronounced for copper.
[0022] The metal may be in the form of a single isotope or an isotopic mixture. The isotopes
may be radioactive isotopes or non-radioactive isotopes. For copper, non-radioactive
isotopes are
63Cu and
65Cu, and radioactive isotopes are preferably
64Cu or
67Cu.
64Cu is a positron emitting isotope of copper, with applications for molecular radiotherapy
and positron emission tomography.
[0023] "Metal salt" means a salt of the metal in the form of a cation with an anion. With
regard to the intended pharmaceutical use of the particle dispersion (a dispersion
of larger particles may also be referred to as a suspension), the skilled person would
understand that the anion should be a pharmaceutically acceptable anion and preferably
water-soluble. The anion may be selected, e.g. from inorganic acid anions such as
halogenides (in particular chlorides, bromides, iodides), sulfates, sulfites, sulfides,
phosphates, nitrates, carbonates; carboxylic acid anions, dicarboxylic acid anions,
tricarboxylic acid anions, sulfonic acid anions, amino acid anions, such as formates,
acetates, propionates, oxalates, succinates, maleinates, fumarates, maleates, citrates,
triflates, gluconates, bis-glycinates.
[0024] "Dithiocarbamate" means a moiety having the formula (R1)(R2)N-CS
2- (also referred to in this text as R1,R2-dithiocarbamate), wherein R1 and R2 are the
same or different and are independently selected from C1-C8 alkyl, C2-C8 alkenyl,
C3-C10 cycloalkyl, C6-C14 aryl, C4-C14 heteroaryl containing at least one heteroatom
selected from O, S, N, C3-C10 heterocyclyl containing at least one heteroatom selected
from O, S, N; or R1 and R2 together with the nitrogen atom on which they are bound
form a heterocycle, wherein -R1-R2- is a C2-C6 alkylene or a C2-C6 alkenylene, wherein
optionally 1-2 carbon atoms may be replaced by heteroatoms selected from O, S, NH.
The moieties forming R1 and R2 may be unsubstituted or further substituted by at least
one substituent selected from C1-C4 alkyl, hydroxy, mercapto, C1-C4 alkoxy, C1-C4
alkylthio, halogen, phenyl, benzyl, keto group, carboxyl group, C1-C4 alkyloxycarbonyl.
[0025] More preferably, R1 and R2 are independently selected from C1-C6 (or C1-C4) alkyl,
C2-C6 (or C2-C4) alkenyl, C3-C6 cycloalkyl, phenyl; or R1 and R2 together with the
nitrogen atom on which they are bound form a heterocycle, wherein -R1-R2- is a C2-C6
alkylene or a C2-C6 alkenylene.
[0026] Most preferably, the dithiocarbamate is diethyldithiocarbamate (R1 and R2 are ethyl).
[0027] Dithiocarbamate can be present in the form of a negatively charged anion, typically
in the dithiocarbamate-metal complex. As a starting compound in the process of the
present invention, it may be used in the form of a neutral compound (R1)(R2)N-C(S)SH
or, preferably, in the form of a salt [(R1)(R2)N-CS
2]
m-Cat
m+. such as alkali metal salt (Cat
+ is an alkali metal cation, m=1), ammonium salt (Cat
+ is an ammonium cation, m=1) or alkaline earth metal salt (Cat
+ is an alkaline earth metal cation, m=2). The skilled person understands which form
is meant or which form is necessary, depending on the context in which the term "dithiocarbamate"
is used.
[0028] "Dithiocarbamate-metal compound" comprises at least one dithiocarbamate moiety and
at least one metal, preferably one metal. For example, the dithiocarbamate-metal compound
may correspond to formula (I)

wherein
M is a metal, preferably copper,
An is a pharmaceutically acceptable anion, preferably as defined herein above,
n is the valence of the metal, typically, n is 1, 2, or 3,
and R1 and R2 are as defined herein above.
[0029] The ratio of the metal to dithiocarbamate may be for example in the range of from
1:5 to 5:1, or in the range of 1:2 to 5:1. The ratio of the metal to dithiocarbamate
may optimally correspond to their stoichiometric ratio in the compound, or to their
stoichiometric ratio ± 20 %, or to their stoichiometric ratio ± 50 %. For example,
for copper the stoichiometric ratio is 1:2.
[0030] "Ligands" are substances which significantly enhance solubility and absorption of
dithiocarbamate-metal complexes by forming the molecular complex assembly particle
and allowing per-oral, topical and parenteral administration of the said particle
in human and veterinary medicine.
[0031] Ligands are selected from water-soluble polymers and detergents.
[0032] The polymers are non-peptide polymers, i.e., polymers not containing L-amino acids
as monomeric units. The polymers may have number-average molecular weight in the range
of 1kDa to 10 MDa. The polymers may include polysaccharides, polyoxyalkylenes, polyalkylene
glycols, polyvinylpyrrolidones, polyvinyl alcohols, polyhydroxyacids, polyacrylates,
polymethacrylates, polyacrylamides, polymethacrylamides, polyethylene glycol ethers,
poly-D-amino acids, stearic acid based polymers, gelatine based polymers, nucleic
acids, mixed copolymers. More particularly, the polymers include cellulose and cellulose
derivatives, glycosaminoglycans and their derivatives, cyclodextrins and their derivatives,
starch and starch derivatives, poloxamers (polyoxyethylene-polyoxypropylene block
copolymers), macrogols (polyethylene glycols) and their derivatives, polyvinylpyrrolidone,
polyvinyl alcohols, polylactic acid, polyacrylates, polymethacrylates, polyacrylamides,
polymethacrylamides, polyethoxylated castor oil, stearic acid based polymers, gelatine
based polymers, ribonucleic acid, deoxyribonucleic acid, polyvinyl caprolactam-polyvinyl
acetate-polyethylene glycol graft co-polymer.
[0033] More specifically, the polymers include cellulose, methylcellulose, hydroxypropylmethylcellulose,
Ficoll, starch, hydroxyethyl starch (Voluven®), hyaluronic acid, chondroitin sulphate,
sulphobutylether-beta-cyclodextrin (Captisol®), poloxamers (e.g. Pluronic® F-127),
macrogol, macrogolglycerol ricinoleate, macrogol 15 hydroxystearate, polyvinylpyrrolidone
(PVP), polyvinyl alcohols (PVA), polylactic acid, poly(N-(2-hydroxypropyl)methacrylamide)
(HPMA), polyethoxylated castor oil (e.g. cremophor), polyvinyl caprolactam-polyvinyl
acetate-polyethylene glycol graft co-polymer (Soluplus® BASF), polyoxyethylated 12-hydroxystearic
acid (Solutol® HS 15 (BASF)), succinylated gelatine (Gelaspan®), ribonucleic acid,
deoxyribonucleic acid.
[0034] Even more specifically, the polymers are selected from Pluronic® F127 (poly(ethylene
glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), polyvinylpyrroline
(povidone), hydroxypropylmethylcellulose, polyvinyl caprolactam-polyvinyl acetate-polyethylene
glycol graft co-polymer (Soluplus®), sulphobutylether-beta cyclodextrin (Captisol®).
[0035] Detergents are pharmaceutically acceptable water-soluble detergents, in particular
steroid-based detergents, more particularly cholates and cholate derivatives such
as cholate salts. The detergents are preferably sodium ursodeoxycholate or sodium
deoxycholate.
[0036] "Aqueous solvent" is water or a water-based buffer, such as phosphate, citrate, acetate,
Tris, HEPES, saline, glucose solution, or other common buffers. Preferably, the aqueous
solvent is sterile.
[0037] The size of the self-assembled complex particles (i.e., molecular complex assemblies)
is 1-2000 nm. Preferably, at least 90 % of the complexes have the size within the
range of 1-500 nm. In some embodiments, at least 50 %, or at least 70 %, or at least
90 % of the particles have the size within the range of 1-1000 nm, or within the range
of 10-500 nm, or within the range of 20-500 nm, or within the range of 1-220 nm. The
complexes sizes and their distributions were measured by Dynamic Light Scattering
(DLS) method and the term "size" or "average size" as used throughout this text refers
to the average size as determined by DLS (Z-average).
[0038] The particulate form consisting of or comprising dithiocarbamate-metal complex and
at least one ligand may be sterile filtered, preferably using a 0.22 micrometer filter.
[0039] The particulate form consisting of or comprising dithiocarbamate-metal complex and
at least one ligand may be provided in the form of an injection or infusion liquid
(solution, dispersion or suspension). The injection or infusion liquid further comprises
at least one pharmaceutically acceptable excipient selected from buffers, surfactants,
chelating agents, isotonicity adjustment agents, pH adjustment agents, preservatives,
stabilisers, antioxidants, reducing agents, solubilizers, metal ions.
[0040] The particulate form consisting of or comprising dithiocarbamate-metal complex and
at least one ligand may be provided in a dry form, in particular in a lyophilized
(freeze-dried) form or in a spray-dried form. The lyophilized formulation typically
further comprises at least one pharmaceutically acceptable excipients selected from
cryoprotectants, buffers, surfactants, chelating agents, isotonicity adjustment agents,
pH adjustment agents, preservatives, stabilisers, antioxidants, reducing agents, solubilizers,
metal ions. The spray-dried formulation may further comprise at least one pharmaceutically
acceptable excipients selected from buffers, surfactants, chelating agents, isotonicity
adjustment agents, pH adjustment agents, preservatives, stabilisers, antioxidants,
reducing agents, solubilizers, metal ions. In particular, lyophilization further improves
stability, and thus facilitates storage and logistics.
[0041] The dry form may be further formulated as a powder for preparing liquid formulations,
or in the forms suitable for peroral administration such as tablets, pills, soft capsules,
hard capsules. The liquid or the dry form may be further formulated in forms suitable
for topical administration such as lotions, ointments, creams, patches, dressings.
[0042] The buffers may include acetate, succinate, citrate, triethanolamine, arginine, phosphate
buffers.
[0043] The surfactants may be, e.g., polysorbate 80, polysorbate 20, poloxamer 188, poloxamer
407.
[0044] The chelating agents may include sodium edetate, glutamic acid, aspartic acid.
[0045] The isotonicity adjustment agents may be selected, e.g., from mannitol, sodium or
potassium chloride, sorbitol, dextrose.
[0046] The pH adjustment agents may be, e.g., acetic acid, hydrochloric acid.
[0047] The stabilizers may include arginine, methionine, glutamic acid, glycine, leucine,
aspartic acid, fatty acids, phosphatidyl choline, ethanolamine, acetyltryptophanate,
PEG, PVP (10, 24, 40), sorbitol, glucose, propylene glycol, ethylene glycol.
[0048] The antioxidants may include glycerin, ascorbic acid, cysteine HCl, thioglycerol,
thioglycolic acid, thiosorbitol, glutathione, alpha-tocopherol, sodium disulfide.
[0049] The reducing agents are, e.g., thiols.
[0050] The solubilizer may be, e.g., alanine.
[0051] The metal ions may include Ca
2+, Ni
2+, Mg
2+, Mn
2+.
[0052] The preservatives may include phenol, benzyl alcohol, chlorobutanol, metacresol and
parabens. Cryoprotectants (or lyoprotectants) may include monosaccharides, disaccharides,
polysaccharides, amino acids, polysaccharides, polymers and other substances with
cryoprotective properties, and derivatives thereof, in particular selected from mannitol,
trehalose, saccharose, albumin, lactose, dextrose, sucrose, glucose, maltose, inositol,
raffinose, inulin, maltodextrin, heparin, 2-hydroxypropyl-β-cyclodextrin, glycerol,
sorbitol, mercaptans, polyethylene glycol, adonitol, amino acids, Tween 80, Pluronic,
Brij, sodium dodecyl sulfate, ascorbic acid, polyvinylpyrrolidone (PVP K15), dextran.
[0053] The percentages, unless indicated otherwise, are w/w %.
[0054] The present invention describes the process of
in-situ self-assembly of dithiocarbamate-copper compound and at least one ligand into a complex
particle. This is attained by a process comprising the steps of:
- (a) solubilizing at least one ligand in an aqueous solvent to a concentration in the
range from 0.001 % (w/w) to saturated solution (preferably from 0.1% to 10% (w/w))
- (b) adding at least one dithiocarbamate dissolved in an aqueous solvent to a concentration
in the range from 1 uM to 100 mM, preferably 1 to 10 mM;
- (c) adding a metal salt solution in an aqueous solvent (e.g. water or water-based
buffer), having the metal salt concentration in the range from 1 uM to 100 M, preferably
1 to 10 mM,
wherein the steps are carried out in the sequence (a), (b), (c) or in the sequence
(a), (c), (b), steps (b) and (c) can be performed simultaneously or subsequently.
[0055] Preferably, at least 10 second-delay accompanied by shaking or vortexing may be made
between individual steps.
[0056] This single-tube reaction leads to rapid spontaneous self-assembly of ligand-dithiocarbamate-metal
particles forming a dispersion.
[0057] In step (b), the dithiocarbamate is preferably in the form of a neutral compound
or salt.
[0058] The ratio of the metal to dithiocarbamate may be for example in the range of from
1:5 to 5:1, or in the range of 1:2 to 1:5. The ratio of the metal to dithiocarbamate
may optimally correspond to their stoichiometric ratio in the compound, or to their
stoichiometric ratio ± 20 %, or to their stoichiometric ratio ± 50 %. For example,
for copper the stoichiometric ratio of metal to dithiocarbamate is 1:2.
[0059] In a preferred embodiment, the molar ratio of metal ions:dithiocarbamate ions is
1:2.
[0060] The use of aqueous solvents yields the nanoparticulate form which is biologically
compatible, without the need for further purification. If organic solvents would be
used, which could be preferred for dissolving dithiocarbamate, the resulting particles
would contain residual amounts of the organic solvents which are difficult to remove.
This decreases the biocompatibility and bioavailability of the particles. Thus, within
the framework of the present invention, it was surprisingly found that when the method
of preparation is carried out in aqueous solvents, a water-soluble nanoparticulate
form with a molecular assembly structure is formed, although dithiocarbamate has a
low solubility in water. The use of aqueous solvents removes the disadvantages which
would be due to the use of organic solvents.
[0061] The formed molecular complex particles of the present invention form a bioavailable
dispersion, and can be administered to a patient in need of such treatment. The dispersion
can be used in therapy, in particular cancer therapy, both chemotherapy and radiotherapy,
such as therapy of solid tumors including melanoma, non-small cell lung cancer, small
cell lung cancer, renal cancer, colorectal cancer, breast cancer, pancreatic cancer,
gastric cancer, bladder cancer, ovarian cancer, uterine cancer, lymphoma, prostate
cancer, myeloma, adenocarcinoma of the colon, nodal or hepatic metastases, brain tumours
and brain metastases. The dispersion can also be used in diagnostics, such as tumour
imaging, e.g., by positron emission tomography.
[0062] It is important to note that when the reaction is performed according to the present
invention, the resulting dispersion of ligand-dithiocarbamate-copper particles allows
direct parenteral, topical or per-oral applications to the treated subject (human
or animal) without the need of additional chemical or physical processing such as
extractions, separations, product cleaning, concentration enhancement etc.
[0063] The starting materials for preparation of the particles according to the present
invention are commercially available in sufficient purity grade and non-expensive,
and the preparation procedure is simple and economically advantageous. For example,
polyvinylpyrrolidone (Povidone), diethyldithiocarbamate and CuCl
2 are commonly commercially available in pharmaceutical grades. Such procedure does
not require costly chemical reactors, processing in additional devices and may simplify
regulatory approval.
[0064] The reaction of the present invention can be performed directly at the bed of the
patient or in the hospital pharmacy using a combination of pharmaceutically acceptable
ingredients, such as the kit of parts as described above. This embodiment may significantly
limit some of the logistic problems related to the storage of the dispersion - a fresh
drug can be prepared when needed with high reproducibility and immediately applied.
[0065] The present invention also enables simple modification of the size of the assembled
particles. By changing the ratio between dithiocarbamate-metal (in particular copper)
complex and the ligands, the formed complex particles are of a different size. Optimum
reaction conditions can be determined to produce complex particles with the optimum
pharmacological properties, as the size of the particle is an important determinant
of its behavior
in-vivo, in particular for biodistribution (e.g. blood-brain barrier penetration) and kinetics.
[0066] The prepared dispersion of complex particles is stable and can be stored for several
weeks at 4 °C without significant degradation or precipitation. The formed complex
particles of ligand-dithiocarbamate-metal can be further stabilized by lyoprotectants
which are mentioned above and processed by drying or lyophilisation to further improve
stability, storage and logistics. Dried complex particles can be repeatedly dissolved
in sterile water-based buffers and used for the therapy. This important aspect of
the ligand-dithiocarbamate-metal complex particle properties is particularly valuable
for both large- or small-scale industrial production, storage and logistics.
[0067] To prove general applicability of the complex particles, the following examples show
preparation and characterization of dithiocarbamate-metal compound with selected pharmaceutically
acceptable excipients or their combinations to demonstrate generic formulation and
cancer targeting. The examples should not be construed as limiting the scope of the
claimed invention.
Brief Description of Drawings
[0068]
Figure 1: table with average sizes of particles measured by the dynamic light scattering
(DLS) prepared according to Examples 1-5. The particles form a polydispersed system
which average size is dependent on the used excipient spanning the range approx. 40
- 1100 nm.
Figure 2 shows representative dynamic light scattering (DLS) spectra of polydispersed
system of particles prepared according to Example 1, 4, 5.
Figure 3 shows representative dynamic light scattering (DLS) spectra of polydispersed
system of particles prepared according to Example 2 depicting the minimum effect of
lyophilisation on the particle size distribution.
Figure 4: table with anticancer activities of particles prepared according to Examples
2, 3, 5 - 13 measured as the cytotoxic effect on selected cancer cell lines cultured
in-vitro under standard conditions.
Figure 5: table with anticancer activities of particles prepared according to Examples
1- 17 measured as the cytotoxic effect on selected cancer cell lines cultured as tumour
spheroids.
Figure 6 depicts the effect of particles prepared according to Examples 2, 3 and 11
on the integrity of tumour spheroids. The figure shows images of 3D spheroids treated
by particles of dithiocarbamate copper compound with various excipients.
Examples
Materials and Methods
[0069] Dynamic Light Scattering (DLS) analyses allowing to determine the average size and
size distribution of the prepared nanoparticles were performed by the Zetasizer Nano
ZS instrument (Malvern, U.K.), with following parameters setting: V = 400 uL, T =
25 °C, Number of runs: 10, Run duration: Is, Number of measurements: 3, Measurement
angle: 173° Backscatter (NIBS default), Cell type: ZEN0040.
Cell lines
[0070] Cell lines were cultured in appropriate medium supplemented with 10% fetal bovine
serum and penicillin/streptomycin; and maintained at humidified, 5% CO2 atmosphere
at 37°C. Cell lines were cultured in media as recommended by the suppliers and involved:
U-2-OS (obtained from European Collection of Authenticated Cell Cultures, ECACC),
CCRF-CEM (ATCC), K562 (ATCC), Cell line A549 (ATCC), K562 (ATCC), DLD-1 (ATCC), DU-145
(ATCC), HeLa (ATCC), BJ (ATCC), MRC5 (ATCC), HCT116 and its p53 gene knock-down counterpart
(HCT116p53-/-), The daunorubicin resistant subline of CCRF-CEM cells (CEM-DNR bulk)
and paclitaxel-resistant subline K562-TAX were selected in our laboratory by the cultivation
of maternal cell lines in increasing concentrations of daunorubicin or paclitaxel,
respectively (Noskova et al 2002).
Cell viability test
[0071] MTS assays were carried out by robotic platform (HighResBiosolutions). Cell suspensions
were prepared and diluted according to the particular cell type and the expected target
cell density (25000 - 35000 cells/mL based on cell growth characteristics). Cells
were added by automatic pipettor (30 µL) into 384 well microtiter plates. All tested
formulations were prepared as described above, four folded dilutions of the intended
test concentration were added in 0.15 µL aliquots at time zero to the microtiter plate
wells by the echo acoustic non-contact liquid handler Echo550 (Labcyte). The experiments
were performed in technical duplicates and three biological replicates at least. The
cells were incubated with the tested compounds for 72 h at 37 °C, in a 5% CO2 atmosphere
at 100% humidity. At the end of the incubation period, the cells were assayed by using
the MTS test. Aliquots (5 µL) of the MTS stock solution were pipetted into each well
and incubated for additional 1-4 h. After this incubation period, the optical density
(OD) was measured at 490 nm with an Envision reader (Perkin Elmer). Tumor cell survival
(TCS) was calculated by using the following equation: TCS = (ODdrug-exposed well/mean
ODcontrol wells) × 100%. The IC50 value, the drug concentration that is lethal to
50% of the tumor cells, was calculated from the appropriate dose-response curves in
Dotmatics software.
Tumour spheroids integrity test
[0072] Spheroids were formed in CellCarrier clear-bottom 384WPs using a modified version
of the liquid-overlay technique. For plate coating, a 0.75% (w/v) low-melting agarose
(Sigma- Aldrich) stock solution was prepared in phenol red-free McCoy's medium without
FBS. The agarose solution was then autoclaved to sterilize. Plates were coated with
15 µL of filtered 0.75% agarose by Multidrop Combi Reagent Dispenser (Thermo Fisher
Scientific Oy, Vantaa, Finland) under sterile conditions. The coated plates were either
used the same day or aseptically stored at 4 °C for up to 2 weeks. Cells were seeded
at a density of 2.5 × 10
4 cells/mL per well in growth medium by Multidrop Reagent Dispenser using a Standard
Tube Dispensing Cassette (Thermo Fisher Scientific Oy). The plates were then centrifuged
at 4g for 10 min and allowed to rest at RT for 1 h. The plates were left undisturbed
for 4 days at 37 °C. The medium was replaced regularly every 3 days by the EL406 washer
manifold, and an equal volume of media was added by the peripump dispenser of the
EL406. Spheroids were routinely monitored in an inverted Axio Observer.D1 fluorescence
microscope (Carl Zeiss Microscopy GmbH, Jena, Germany).
High-Content Imaging and Image Analyses
[0073] HCT116, HeLa, DU145 and DLD1 spheroids were treated on day 6 by complex particles
of dithiocarbamate copper compound with excipients or by copper diethyldithiocarbamate
solution in DMSO for 72 h and imaged by a fully automated CellVoyager High-Content
Imaging System (Model CV7000; Yokogawa Electric Corporation, Tokyo, Japan) using a
4× air objective. Bright-field z-stack images of spheroids were taken at an interval
of 10-20 µm. Images were stored in the TIFF format, and spheroid characteristics were
analyzed using an in-house algorithm developed in MatLab R2013b (MathWorks, Inc.,
Natick, MA). Briefly, the sharpest image with the maximum L1-norm of the image gradient
was selected from the z-stack images. The visible well boundary was cropped from the
image to prevent interference with subsequent image analysis. Next, the spheroid was
localized by performing convolution with a predefined circular filter. Image segmentation
was performed to correctly distinguish the spheroid (darker) from the lighter background.
Once identified by the optimal threshold, spheroid characteristics, such as area and
minor and major axis lengths, were computed in pixels.
[0074] Data were analyzed using GraphPad Prism (version 6; San Diego, CA).
HPLC/MS analysis of copper-dithiocarbamate complex (CuET)
[0075] The HR-MRM analysis was performed on HPLC-ESI-QTOF system consisting of HPLC chromatograph
Thermo UltiMate 3000 with AB Sciex TripleTOF 5600+ mass spectrometer, using the DuoSpray
ESI source operated at ion source voltage 5500 V, ion source gas flow rates 40 units,
curtain gas flow rate 30 units, declustering potential 100 V and temperature 400°C.
Data were acquired in Product ion mode with two parent masses 358.9 and 360.9 for
analysis of CuET. Chromatographic separation was done by PTFE column especially designed
for analysis of strong metal chelators filled by C18 sorbent. Analysis was performed
at room temperature and flow rate 1500 µL/min with isocratic chromatography. Mobile
phase consisted of HPLC grade acetone (Lachner) 99.9%, HPLC water (Merck Millipore)
0.1% and 0.03% HPLC formic acid (Sigma). Acquired mass spectra were evaluated in software
PeakView 1.2, where extracted ion chromatograms of transitions 88.0 and 116.0 (common
for both parent masses) with 0.1 mass tolerance was Gaussian smoothened with width
of 2 points. Peak area was then recorded and recalculated to ng/ml according to calibration
curve.
Sample preparation for HPLC/MS analysis
[0076] Liquid nitrogen-frozen biological samples were cut into small pieces by scalpel.
Sample (30-100 mg) was immediately processed by homogenization in 100% acetone in
ratio 1:10 sample vs. acetone (for plasma or serum the ratio was 1:4). Homogenization
was done in a table homogenizer (Retsch MM301) placed in a cold room (4°C) in 2 ml
Eppendorf tube with 2 glass balls (5mm) for 1min, 30Hz. Next, tube was immediately
centrifuged at 4°C, 20.000G, 2min. Supernatant was decanted into a new 1,5 ml Eppendorf
tube and immediately centrifuged for 30min using small table centrifuge (BioSan FVL-2400N)
placed inside a -80°C freezer. Supernatant was quickly decanted into glass HPLC vial
and kept at -80°C not longer than 6 hours. Just before the HPLC analysis the vial
was placed into the pre-cooled (4°C) LC-sample rack and immediately analyzed. To enable
approximate quantification of analyzed CuET, calibration curve was prepared. Standards
were then processed similarly as the samples described above. Blood plasma samples
were processed using similar procedure, just omitting the tissue homogenization step.
Mice in-vivo experiments
[0077] Acute toxicity study was done in NMRI mice animal model. Amount of complex particle
of dithiocarbamate copper compound prepared according to example 1 and received by
each animal was 1, 3 and 5mg/kg intraperitoneally or intravenously. Maximum tolerated
dose was defined as a concentration of the formulated drug which does not affect survival
or induce morbidity in experimental animals.
[0078] Measurement of blood pharmacokinetics and tissue distribution was performed in mice
injected with dithiocarbamate copper molecular assembly (at concentration corresponding
to 1mg/kg CuET). Animals were sacrificed at indicated time points (typically 0.5,
1, 3, 6, 9, 12, 24 and 36 hours post injection), blood was collected and serum separated,
selected organs were removed, snap frozen and stored together with serum at -80°C
until analysis.
[0079] Repeat-dose toxicity study was done in was done in NMRI mice animal model. Amount
of complex particle of dithiocarbamate copper compound prepared according to example
1 and administered intraperitoneally at the dose of 1, 3 or 5 mg/kg of dithiocarbamate
copper compound prepared according to example 1 was administered to each animal daily
on days 1-5 and 8-12.
[0080] All aspects of the animal studies met the acceptance criteria for the care and experimental
use of laboratory animals, and protocols were approved by the Animal Research Committee
of Palacky University in Olomouc.
[0081] Chemicals used:
Methylcellulose (Sigma-Aldrich), Hydroxypropylmethylcellulose(Sigma-Aldrich), Pluronic®
F-127 (Sigma-Aldrich), polyvinylpyrrolidone (Kollidon®-17 (BASF), PVP40 (Sigma-Aldrich),
PVP360 (Sigma-Aldrich)), poly-methacrylamides (e.g. poly(N-(2-hydroxypropyl)methacrylamide)
(HPMA)) (Sigma-Aldrich), cremophor (Sigma-Aldrich), Soluplus® (BASF), Gelofusine®
4% (Braun), poly-D-lysine (Sigma-Aldrich), Ficoll 400 (Sigma-Aldrich), Kolliphor®
(BASF), Captisol® (Abmole), Solutol® HS 15 (BASF), hydroxyethyl starch (Voluven 10%,
Fresenius Kabi), hyaluronic acid (Sigma-Aldrich), chondroitin sulphate (Sigma-Aldrich),
deoxyribonucleic acid (salmon sperm DNA) (Sigma-Aldrich), sodium deoxycholate (Sigma-Aldrich).
[0082] Percentages, unless indicated otherwise, are w/w %.
EXAMPLE 1
[0083] Preparation of dispersion of complex particles from 2% polyvinylpyrrolidone (PVP40,
MW 40 kDa) and diethyldithiocarbamate and copper chloride salt.
Procedure:
[0084] Solution of 2% PVP40 in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 2% PVP40 to reach final
concentration 5.6 mM, followed by brief stirring. To the 2% PVP40 solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0085] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-PVP40
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 50+/- 10nm in diameter (see Figure1).
The DLS spectra analyses also showed that the particles form a polydispersed system
where the size of the particles spanned the range ca 20 - 100 nm with the largest
fraction of 40-50 nm (see Figure 2). The dispersion of particles was also tested in
biological experiments involving cytotoxicity tests on cell grown in-vitro under standard
cultivation conditions. The panel consisted of human cell lines derived from cancers
including acute lymphoblastic leukemia (CCRF-CEM), lung carcinoma (A549), colorectal
adenocarcinoma (HCT116) and its p53 gene knock-down counterpart (HCT116p53-/-) is
a model of human cancers with p53 mutation frequently associated with poor prognosis.
The daunorubicin resistant subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant
subline K562-TAX were selected in our laboratory by the cultivation of maternal cell
lines in increasing concentrations of daunorubicin or paclitaxel, respectively (Noskova
et al. 2002). The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary
(normal) cells including normal human fibroblasts (BJ, MRC5). Toxicity of the particles
was tested in the MTS - based cell viability assay (see Figure 4). The dispersion
of particles was also tested in biological experiments involving cytotoxicity tests
on cancer cells spheroids mimicking tumour microenvironment and physiology. Tested
tumour spheroid models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal
adenocarcinoma), DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma)
cell lines (see Figure 5). Importantly, diethyldithiocarbamate-copper-PVP40 complex
particles often display much better potency as neat diethyldithiocarbamate-copper
powder dissolved in dimethyl sulfoxide (DMSO) (see Figure 5).
[0086] The dispersion of complex particles was also tested in-vivo for acute and repeated
dose toxicity intraperitoneally in mice showing MTD at doses corresponding to CuET
concentration >3 and 1 mg/kg, respectively.
[0087] The dispersion of complex particles was also tested for the possibility of drying
and subsequent resolubilization. The nanoparticles were freeze-dried under vacuum
for 16 hours. Dried powder was stored at 4°C for one week and then solubilized with
sterile water. Resulting re-solubilized particles were analysed by DLS displaying
minimal changes in physical properties.
EXAMPLE 2
[0088] Preparation of dispersion of complex particles from 5% polyvinylpyrrolidone (PVP40,
MW 40 kDa) and diethyldithiocarbamate and copper chloride salt.
Procedure:
[0089] Solution of 5% PVP40 in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 5% PVP40 to reach final
concentration 5.6 mM, followed by brief stirring. To the 5% PVP40 solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0090] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-PVP40
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 50±10nm in diameter (see Figure 1).
Size increase of diethyldithiocarbamate-copper-PVP40 complex particles was observed
when 5% PVP solution was used for particle preparation. Such observation is proving
that for instance, the original excipient concentration can affect the resulting size
of particles. The DLS spectra analyses also showed that the particles form a polydispersed
system where the size of the particles spanned the range ca 20 - 100 nm with the largest
fraction of 40-50 nm (see Figure 2). The dispersion of particles was also tested in
biological experiments involving cytotoxicity tests on cell grown in-vitro under standard
cultivation conditions. The panel consisted of human cell lines derived from cancers
including acute lymphoblastic leukemia (CCRF-CEM), lung carcinoma (A549), colorectal
adenocarcinoma (HCT116) and its p53 gene knock-down counterpart (HCT116p53-/-) is
a model of human cancers with p53 mutation frequently associated with poor prognosis.
The daunorubicin resistant subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant
subline K562-TAX were selected in our laboratory by the cultivation of maternal cell
lines in increasing concentrations of daunorubicin or paclitaxel, respectively (Noskova
et al. 2002). The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary
(normal) cells including normal human fibroblasts (BJ, MRC5). Toxicity of the particles
was tested in the MTS - based cell viability assay (see Figure 4). The dispersion
of particles was also tested in biological experiments involving cytotoxicity tests
on cancer cells spheroids mimicking tumour microenvironment and physiology. Tested
tumour spheroid models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal
adenocarcinoma), DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma)
cell lines (see Figure 5). Importantly, diethyldithiocarbamate-copper-PVP40 complex
particles often display much better potency as neat diethyldithiocarbamate-copper
powder dissolved in dimethyl sulfoxide (DMSO) (see Figure 5).
[0091] The dispersion of complex particles was also tested for the possibility of drying
and subsequent resolubilization. The nanoparticles were freeze-dried under vacuum
for 16 hours. The dried powder was stored at 4°C for one week and then solubilized
with sterile water. Resulting re-solubilized particles were analysed by DLS displaying
minimal changes in the physical properties (Figure 1 - table 1, Figure 3).
EXAMPLE 3
[0092] Preparation of dispersion of complex particles from 0.1% hyaluronic acid (HA) and
diethyldithiocarbamate and copper chloride salt.
Procedure:
[0093] A solution of 0,1% hyaluronic acid (HA) in water is prepared. Diethyldithiocarbamate
sodium salt (DTC) is solubilised in water in concentration 280 mM and added to 0,1%
HA to reach final concentration 0.56 mM, followed by brief stirring. To the 0,1% HA
solution containing 0.56 mM DTC is added sterile copper (ii) chloride (1 M concentration
in water) to final concentration 0.28 mM, followed by brief stirring.
Results:
[0094] The resulting solution contains 0.28 mM (0.1 mg/ml) of diethyldithiocarbamate-copper-
HA complex particles. The complex particles resulting from this particular reaction
were further analysed by DLS showing average size of 1076 +/- 63 nm in diameter (Figure
1). The dispersion of particles was also tested in biological experiments involving
cytotoxicity tests on cell grown in-vitro under standard cultivation conditions. The
panel consisted of human cell lines derived from cancers including lung carcinoma
(A549), colorectal adenocarcinoma (HCT116) and its p53 gene knock-down counterpart
(HCT116p53-/-) is a model of human cancers with p53 mutation frequently associated
with poor prognosis. The daunorubicin resistant subline of CCRF-CEM cells (CEM-DNR
bulk) and paclitaxel-resistant subline K562-TAX were selected in our laboratory by
the cultivation of maternal cell lines in increasing concentrations of daunorubicin
or paclitaxel, respectively (Noskova et al. 2002). The osteosarcoma (U2OS), chronic
myelogenous leukemia (K562) and primary (normal) cells including normal human fibroblasts
(MRC5). Toxicity of the particles was tested in the MTS - based cell viability assay
(see Figure 4). The dispersion of particles was also tested in biological experiments
involving cytotoxicity tests on cancer cells spheroids mimicking tumour microenvironment
and physiology. Tested tumour spheroid models included HCT116 (colorectal adenocarcinoma),
DLD1 (colorectal adenocarcinoma), DU145 (metastatic prostate cancer) and HeLa (endocervical
adenocarcinoma) cell lines (see Figure 5). Importantly, diethyldithiocarbamate-copper-HA
complex particles often display much better potency as neat diethyldithiocarbamate-copper
powder dissolved in dimethyl sulfoxide (DMSO) (see Figure 5).
EXAMPLE 4
[0095] Preparation of dispersion of complex particles from 0,75% sodium deoxycholate (DCH)
and diethyldithiocarbamate and copper chloride salt.
Procedure:
[0096] Solution of 0.75% DCH in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 0.75% DCH to reach final
concentration 5.6 mM, followed by brief stirring. To the 0.75% DCH solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0097] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-DCH
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 46.4 +/- 1,9 nm in diameter (Figure
1). The DLS spectra analyses also showed that the particles form a polydispersed system
where the size of the particles spanned the range ca 20 - 100 nm with the largest
fraction of 40-50 nm (Figure 2). The dispersion of particles was also tested in biological
experiments involving cytotoxicity tests on cell grown in-vitro under standard cultivation
conditions. The panel consisted of human cell lines derived from cancers including
acute lymphoblastic leukemia (CCRF-CEM), lung carcinoma (A549), colorectal adenocarcinoma
(HCT116) and its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human
cancers with p53 mutation frequently associated with poor prognosis. The daunorubicin
resistant subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline
K562-TAX were selected in our laboratory by the cultivation of maternal cell lines
in increasing concentrations of daunorubicin or paclitaxel, respectively (Noskova
et al. 2002). The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary
(normal) cells including normal human fibroblasts (BJ, MRC5). Toxicity of the particles
was tested in the MTS - based cell viability assay. The dispersion of particles was
also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-DCH complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
[0098] The dispersion of complex particles was also tested in-vivo for acute and repeated
dose toxicity intraperitoneally in mice showing MTD at doses corresponding to CuET
concentration >5 and 1.5 mg/kg, respectively.
[0099] The dispersion of complex particles was also tested for the possibility of drying
and subsequent resolubilisation. The nanoparticles were freeze-dried under vacuum
for 16 hours. Dried powder was stored at 4°C for one week and then solubilized with
sterile water. Resulting re-solubilized particles were analysed by DLS displaying
minimal changes in the physical properties (Figure 1, Figure 3).
EXAMPLE 5
[0100] Preparation of dispersion of complex particles from 5% Soluplus® and diethyldithiocarbamate
and copper chloride salt.
Procedure:
[0101] Solution of 5% Soluplus® in water is prepared. Diethyldithiocarbamate sodium salt
(DTC) is solubilised in water in concentration 280 mM and added to 5% Soluplus® to
reach final concentration 5.6 mM, followed by brief stirring. To the 5% Soluplus®
solution containing 5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration
in water) to final concentration 2.8 mM, followed by brief stirring.
Results:
[0102] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-Soluplus®
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 53,4 +/- 2,7 nm in diameter (Figure
1). The DLS spectra analyses also showed that the particles form a polydispersed system
where the size of the particles spanned the range ca 20 - 100 nm with the largest
fraction of 40-50 nm (see Figure 2). The dispersion of particles was also tested in
biological experiments involving cytotoxicity tests on cells grown in-vitro under
standard cultivation conditions. The panel consisted of human cell lines derived from
cancers including acute lymphoblastic leukemia (CCRF-CEM), lung carcinoma (A549),
colorectal adenocarcinoma (HCT116) and its p53 gene knock-down counterpart (HCT116p53-/-)
is a model of human cancers with p53 mutation frequently associated with poor prognosis.
The daunorubicin resistant subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant
subline K562-TAX were selected in our laboratory by the cultivation of maternal cell
lines in increasing concentrations of daunorubicin or paclitaxel, respectively (Noskova
et al. 2002). The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary
(normal) cells including normal human fibroblasts (BJ, MRC5). Toxicity of the particles
was tested in the MTS - based cell viability assay (see Figure 4). The dispersion
of particles was also tested in biological experiments involving cytotoxicity tests
on cancer cells spheroids mimicking tumour microenvironment and physiology. Tested
tumour spheroid models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal
adenocarcinoma), DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma)
cell lines (Figure 5). Importantly, diethyldithiocarbamate-copper-Soluplus® complex
particles often display much better potency as neat diethyldithiocarbamate-copper
powder dissolved in dimethyl sulfoxide (DMSO) (Figure 5).
[0103] The dispersion of complex particles was also tested for the possibility of drying
and follow-up resolubilisation. The nanoparticles were freeze-dried under vacuum for
16 hours. Dried powder was stored at 4°C for one week and then solubilized with sterile
water. Resulting re-solubilized particles were analysed by DLS displaying minimal
changes in the physical properties.
EXAMPLE 6
[0104] Preparation of dispersion of complex particles from 0.2 % methylcellulose (MC) and
diethyldithiocarbamate and copper chloride salt.
Procedure:
[0105] Solution of 0.2% MC in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 0.2% MC to reach final
concentration 5.6 mM, followed by brief stirring. To the 0.2% MC solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0106] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-MC
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 233,6 ± 98,13 nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively (Noskova et al. 2002).
The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary (normal)
cells including normal human fibroblasts (MRC5). Toxicity of the particles was tested
in the MTS - based cell viability assay (Figure 4). The dispersion of particles was
also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-MC complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
EXAMPLE 7
[0107] Preparation of dispersion of complex particles from 5 % polyvinylpyrrolidone (PVP360,
MW 360 kDa) and diethyldithiocarbamate and copper chloride salt.
Procedure:
[0108] Solution of 5% PVP360 in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 5% PVP360 to reach final
concentration 5.6 mM, followed by brief stirring. To the 5% PVP360 solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0109] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-PVP360
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 451,13 ± 342,62 nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively (Noskova et al. 2002).
The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary (normal)
cells including normal human fibroblasts (MRC5). Toxicity of the particles was tested
in the MTS - based cell viability assay (Figure 4). The dispersion of particles was
also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-PVP360 complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
EXAMPLE 8
[0110] Preparation of dispersion of complex particles from 5 % hydroxyethyl starch (HES)
and diethyldithiocarbamate and copper chloride salt.
Procedure:
[0111] A commercially available solution of 10% HES (Voluven®) is half diluted by H
2O to 5% HES which is used. Diethyldithiocarbamate sodium salt (DTC) is solubilised
in water in concentration 280 mM and added to 5% HES to reach final concentration
5.6 mM, followed by brief stirring. To the 5% HES solution containing 5.6 mM DTC is
added sterile copper (ii) chloride (1 M concentration in water) to final concentration
2.8 mM, followed by brief stirring.
Results:
[0112] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-HES
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 57,25 ± 20,93 nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively (Noskova et al. 2002).
The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary (normal)
cells including normal human fibroblasts (MRC5). Toxicity of the particles was tested
in the MTS - based cell viability assay (Figure 4). The dispersion of particles was
also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-HES complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
EXAMPLE 9
[0113] Preparation of dispersion of complex particles from 4 % succinylated gelatine (SG)
and diethyldithiocarbamate and copper chloride salt.
Procedure:
[0114] Commercially available solution of 4% SG (Gelofusine®) is used. Diethyldithiocarbamate
sodium salt (DTC) is solubilised in water in concentration 280 mM and added to 5%
HES to reach final concentration 5.6 mM, followed by brief stirring. To the 5% SG
solution containing 5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration
in water) to final concentration 2.8 mM, followed by brief stirring.
Results:
[0115] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-SG
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 28,1 ± 10,2 nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively (Noskova et al. 2002).
The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary (normal)
cells including normal human fibroblasts (MRC5). Toxicity of the particles was tested
in the MTS - based cell viability assay (Figure 4). The dispersion of particles was
also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-SG complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
EXAMPLE 10
[0116] Preparation of dispersion of complex particles from 2 % chondroitin sulfate (CHS)
and diethyldithiocarbamate and copper chloride salt.
Procedure:
[0117] Solution of 2% CHS in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 2% CHS to reach final
concentration 5.6 mM, followed by brief stirring. To the 2% CHS solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0118] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-CHS
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 298.17 ± 32.07 nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively (Noskova et al. 2002).
The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary (normal)
cells including normal human fibroblasts (MRC5). Toxicity of the particles was tested
in the MTS - based cell viability assay (see Figure 4). The dispersion of particles
was also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-CHS complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
EXAMPLE 11
[0119] Preparation of dispersion of complex particles from 5 % Pluronic® F-127 (PL) and
diethyldithiocarbamate and copper chloride salt.
Procedure:
[0120] Solution of 5% PL in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 5% PL to reach final
concentration 5.6 mM, followed by brief stirring. To the 5% PL solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0121] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-PL
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 74,54 ± 9,5 nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively. The osteosarcoma (U2OS),
chronic myelogenous leukemia (K562) and primary (normal) cells including normal human
fibroblasts (MRC5). Toxicity of the particles was tested in the MTS - based cell viability
assay (Figure 4). The dispersion of particles was also tested in biological experiments
involving cytotoxicity tests on cancer cells spheroids mimicking tumour microenvironment
and physiology. Tested tumour spheroid models included HCT116 (colorectal adenocarcinoma),
DLD1 (colorectal adenocarcinoma), DU145 (metastatic prostate cancer) and HeLa (endocervical
adenocarcinoma) cell lines (Figure 5). Importantly, diethyldithiocarbamate-copper-PL
complex particles often display much better potency as neat diethyldithiocarbamate-copper
powder dissolved in dimethyl sulfoxide (DMSO) (Figure 5). The dispersion of complex
particles was also tested in-vivo for acute and repeated dose toxicity intraperitoneally
in mice showing MTD at doses corresponding to CuET concentration >5 and >5 mg/kg,
respectively. To measure circulating CuET concentrations, mice were dosed with single
intraperitoneal or intravenous diethyldithiocarbamate-copper-PL complex particles
(corresponding to 1 mg/kg of CuET) and sacrificed at 0.5, 1, 3, 6, 9, 12, 24, 36 hour
time points. Serum was collected and frozen for analysis. Maximum measured concentration
of CuET in serum was 15,92 nmol/l at 1 hour after intraperitoneal and 110.91 nmol/l
at 0.5 hour after intravenous administration. Brain tissue was also collected and
frozen for analysis. Maximum measured concentration of CuET in brain tissue was 2.21
nmol/l at 1 hour after intraperitoneal and 23,39 nmol/l at 0.5 hour after intravenous
administration.
EXAMPLE 12
[0122] Preparation of dispersion of complex particles from 5% cremophor (CR) and diethyldithiocarbamate
and copper chloride salt.
Procedure:
[0123] Solution of 5% CR in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 5% CR to reach final
concentration 5.6 mM, followed by brief stirring. To the 5% CR solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0124] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-CR
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 262,4 ± 4,87 nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively (Noskova et al. 2002).
The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary (normal)
cells including normal human fibroblasts (MRC5). Toxicity of the particles was tested
in the MTS - based cell viability assay (see Figure 4). The dispersion of particles
was also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-CR complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
EXAMPLE 13
[0125] Preparation of dispersion of complex particles from 5% Solutol® HS 15 (SO) and diethyldithiocarbamate
and copper chloride salt.
Procedure:
[0126] Solution of 5% SO in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 5% SO to reach final
concentration 5.6 mM, followed by brief stirring. To the 5% SO solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0127] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-SO
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 45,08 ± 23,32 nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively (Noskova et al. 2002).
The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary (normal)
cells including normal human fibroblasts (MRC5). Toxicity of the particles was tested
in the MTS - based cell viability assay (Figure 4). The dispersion of particles was
also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-SO complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
EXAMPLE 14
[0128] Preparation of dispersion of complex particles from 0.2% Salmon sperm DNA (DNA) and
diethyldithiocarbamate and copper chloride salt.
Procedure:
[0129] Solution of 0.2% DNA in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 0.2% DNA to reach final
concentration 5.6 mM, followed by brief stirring. To the 0.2% DNA solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0130] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-
DNA complex particles. The dispersion of particles was tested in biological experiments
involving cytotoxicity tests on cells grown in-vitro under standard cultivation conditions.
The panel consisted of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma
(HCT116) and its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human
cancers with p53 mutation frequently associated with poor prognosis. The daunorubicin
resistant subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline
K562-TAX were selected in our laboratory by the cultivation of maternal cell lines
in increasing concentrations of daunorubicin or paclitaxel, respectively (Noskova
et al. 2002). The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary
(normal) cells including normal human fibroblasts (MRC5). Toxicity of the particles
was tested in the MTS - based cell viability assay (Figure 4). The dispersion of particles
was also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-DNA complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
EXAMPLE 15
[0131] Preparation of dispersion of complex particles from 5% Kollidon® 17 (K17) and diethyldithiocarbamate
and copper chloride salt.
Procedure:
[0132] Solution of 5% K17 in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 5% K17 to reach final
concentration 5.6 mM, followed by brief stirring. To the 5% K17 solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0133] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-K17
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 56,6 ± 12,16 nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively. The osteosarcoma (U2OS),
chronic myelogenous leukemia (K562) and primary (normal) cells including normal human
fibroblasts (MRC5). Toxicity of the particles was tested in the MTS - based cell viability
assay (Figure 4). The dispersion of particles was also tested in biological experiments
involving cytotoxicity tests on cancer cells spheroids mimicking tumour microenvironment
and physiology. Tested tumour spheroid models included HCT116 (colorectal adenocarcinoma),
DLD1 (colorectal adenocarcinoma), DU145 (metastatic prostate cancer) and HeLa (endocervical
adenocarcinoma) cell lines (Figure 5). Importantly, diethyldithiocarbamate-copper-K17
complex particles often display much better potency as neat diethyldithiocarbamate-copper
powder dissolved in dimethyl sulfoxide (DMSO) (Figure 5).
[0134] The dispersion of complex particles was also tested in-vivo for acute and repeated
dose toxicity intraperitoneally in mice showing MTD at doses corresponding to CuET
concentration >5 and >5 mg/kg, respectively. To measure circulating CuET concentrations,
mice were dosed with single intraperitoneal or intravenous diethyldithiocarbamate-copper-K17
complex particles (corresponding to 1 mg/kg of CuET) and sacrificed at 0.5, 1, 3,
6, 9, 12, 24, 36 hour time points. Serum was collected and frozen for analysis. Maximum
measured concentration of CuET in serum was 38,23 nmol/l at 0.5 hour after intraperitoneal
and 23,93 nmol/l at 0.5 hour after intravenous administration. Brain tissue was also
collected and frozen for analysis. Maximum measured concentration of CuET in brain
tissue was 16,38 nmol/l at 1 hour after intraperitoneal and 14,99 nmol/l at 0.5 hour
after intravenous administration.
EXAMPLE 16
[0135] Preparation of dispersion of complex particles from 5% Ficol 400 (F400) and diethyldithiocarbamate
and copper chloride salt.
Procedure:
[0136] Solution of 5% F400 in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 5% F400 to reach final
concentration 5.6 mM, followed by brief stirring. To the 5% F400 solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0137] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-F400
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 11,46 ± 3,68 nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively (Noskova et al. 2002).
The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary (normal)
cells including normal human fibroblasts (MRC5). Toxicity of the particles was tested
in the MTS - based cell viability assay (see Figure 4). The dispersion of particles
was also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-F400 complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
EXAMPLE 17
[0138] Preparation of dispersion of complex particles from 5% Kolliphor EL (KEL) and diethyldithiocarbamate
and copper chloride salt.
Procedure:
[0139] Solution of 5% KEL in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 5% KEL to reach final
concentration 5.6 mM, followed by brief stirring. To the 5% KEL solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0140] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-KEL
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 158,67 ± 24,31nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively (Noskova et al. 2002).
The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary (normal)
cells including normal human fibroblasts (MRC5). Toxicity of the particles was tested
in the MTS - based cell viability assay (Figure 4). The dispersion of particles was
also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-KEL complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
EXAMPLE 18
[0141] Preparation of dispersion of complex particles from 5% Captisol® (Cap) and diethyldithiocarbamate
and copper chloride salt.
Procedure:
[0142] Solution of 5% Cap in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 5% Cap to reach final
concentration 5.6 mM, followed by brief stirring. To the 5% Cap solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0143] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-Cap
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 155,93 ± 13,93 nm in diameter (Figure
1). The dispersion of particles was tested in biological experiments involving cytotoxicity
tests on cells grown in-vitro under standard cultivation conditions. The panel consisted
of human cell lines as lung carcinoma (A549), colorectal adenocarcinoma (HCT116) and
its p53 gene knock-down counterpart (HCT116p53-/-) is a model of human cancers with
p53 mutation frequently associated with poor prognosis. The daunorubicin resistant
subline of CCRF-CEM cells (CEM-DNR bulk) and paclitaxel-resistant subline K562-TAX
were selected in our laboratory by the cultivation of maternal cell lines in increasing
concentrations of daunorubicin or paclitaxel, respectively (Noskova et al. 2002).
The osteosarcoma (U2OS), chronic myelogenous leukemia (K562) and primary (normal)
cells including normal human fibroblasts (MRC5). Toxicity of the particles was tested
in the MTS - based cell viability assay (Figure 4). The dispersion of particles was
also tested in biological experiments involving cytotoxicity tests on cancer cells
spheroids mimicking tumour microenvironment and physiology. Tested tumour spheroid
models included HCT116 (colorectal adenocarcinoma), DLD1 (colorectal adenocarcinoma),
DU145 (metastatic prostate cancer) and HeLa (endocervical adenocarcinoma) cell lines
(Figure 5). Importantly, diethyldithiocarbamate-copper-Cap complex particles often
display much better potency as neat diethyldithiocarbamate-copper powder dissolved
in dimethyl sulfoxide (DMSO) (Figure 5).
[0144] The dispersion of complex particles was also tested in-vivo for acute and repeated
dose toxicity intraperitoneally in mice showing MTD at doses corresponding to CuET
concentration >5 and >5 mg/kg, respectively.
EXAMPLE 19
[0145] Preparation of dispersion of complex particles from 5% poly(N-(2-hydroxypropyl)methacrylamide)
(HPMA) and diethyldithiocarbamate and copper chloride salt.
Procedure:
[0146] Solution of 5% HPMA in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 5% HPMA to reach final
concentration 5.6 mM, followed by brief stirring. To the 5% HPMA solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0147] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-HPMA
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 69,54 ± 11,99 nm in diameter (Figure
1).
EXAMPLE 20
[0148] Preparation of dispersion of complex particles from 1% hydroxypropylmethylcellulose
(HPMC) and diethyldithiocarbamate and copper chloride salt.
Procedure:
[0149] Solution of 1% HPMC in water is prepared. Diethyldithiocarbamate sodium salt (DTC)
is solubilised in water in concentration 280 mM and added to 1% HPMC to reach final
concentration 5.6 mM, followed by brief stirring. To the 1% HPMA solution containing
5.6 mM DTC is added sterile copper (ii) chloride (1 M concentration in water) to final
concentration 2.8 mM, followed by brief stirring.
Results:
[0150] The resulting solution contains 2.8 mM (1 mg/ml) of diethyldithiocarbamate-copper-HPMC
complex particles. The complex particles resulting from this particular reaction were
further analysed by DLS showing average size of 330 ± 23,16 nm in diameter (Figure
1).
[0151] The dispersion of complex particles was also tested in-vivo for acute dose toxicity
intraperitoneally and intravenously in mice showing MTD at doses corresponding to
CuET concentration 3 and >5 mg/kg, respectively.
1. A molecular complex assembly particulate form consisting of or comprising dithiocarbamate-metal
compound and least one ligand selected from polymers and detergents, said particle
being preferably substantially free of organic solvents.
2. The particulate form according to claim 1, wherein the metal is selected from copper,
zinc, silver and gold, preferably the metal is copper.
3. The particulate form according to claim 1, wherein the metal is selected from 63Cu, 65Cu, 64Cu and mixtures thereof.
4. The particulate form according to any one of the preceding claims, wherein the dithiocarbamate
has a formula (R1)(R2)N-CH2S2-, wherein R1 and R2 are the same or different and are independently selected from
C1-C8 alkyl, C2-C8 alkenyl, C3-C10 cycloalkyl, C6-C14 aryl, C4-C14 heteroaryl containing
at least one heteroatom selected from O, S, N, C3-C10 heterocyclyl containing at least
one heteroatom selected from O, S, N; or R1 and R2 together with the nitrogen atom
on which they are bound form a heterocycle, wherein -R1-R2- is a C2-C6 alkylene or
a C2-C6 alkenylene, wherein optionally 1-2 carbon atoms may be replaced by heteroatoms
selected from O, S, NH; and
the moieties forming R1 and R2 may be unsubstituted or further substituted by at least
one substituent selected from C1-C4 alkyl, hydroxy, mercapto, C1-C4 alkoxy, C1-C4
alkylthio, halogen, phenyl, benzyl, keto group, carboxyl group, C1-C4 alkyloxycarbonyl.
5. The particulate form according to claim 4, wherein R1 and R2 are independently selected
from C1-C6 (or C1-C4) alkyl, C2-C6 (or C1-C4) alkenyl, C3-C6 cycloalkyl, phenyl; or
R1 and R2 together with the nitrogen atom on which they are bound form a heterocycle,
wherein -R1-R2- is a C2-C6 alkylene or a C2-C6 alkenylene.
6. The particulate form according to any one of the preceding claims, wherein the ligands
are water-soluble polymers selected from polysaccharides, polyoxyalkylenes, polyalkylene
glycols, polyvinylpyrrolidones, polyvinyl alcohols, polyhydroxyacids, polyacrylates,
polymethacrylates, polyacrylamides, polymethacrylamides, polyethylene glycol ethers,
poly-D-amino acids, stearic acid based polymers, gelatine based polymers, nucleic
acids, mixed copolymers; or the ligands are cholates or cholate derivatives.
7. The particulate form according to any one of the preceding claims, wherein the ligands
are selected from poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene
glycol), polyvinylpyrrolidone, hydroxypropylmethylcellulose, polyvinyl caprolactam-polyvinyl
acetate-polyethylene glycol graft co-polymer, sulphobutylether-beta cyclodextrin,
sodium ursodeoxycholate, sodium deoxycholate.
8. A process for preparation of the molecular complex assembly particulate form according
to any one of the preceding claims, wherein the molecular complex assembly particular
form is prepared by combining at least one ligand with a first component selected
from a dithiocarbamate or a metal salt in an aqueous solvent, and simultaneously or
subsequently adding a second component selected from a dithiocarbamate or a metal
salt, whereas if the first component is a dithiocarbamate, then the second component
is a metal salt; and if the first component is a metal salt, then the second component
is a dithiocarbamate.
9. The process according to claim 8, comprising the steps of:
(a) solubilizing at least one ligand in an aqueous solvent to a concentration in the
range from 0.001% (w/w) to saturated solution;
(b) adding at least one dithiocarbamate dissolved in an aqueous solvent in the range
from 1 uM to 100 mM, preferably 1 to 10 mM;
(c) adding a metal salt solution in an aqueous solvent, having the metal salt concentration
in the range from 1 uM to 100 M, preferably 1 to 10 mM,
wherein the steps are carried out in the sequence (a), (b), (c) or in the sequence
(a), (c), (b) or steps (b) and (c) are carried out simultaneously;
(d) optionally lyophilizing or drying the resulting solution.
10. The process according to any one of claims 8 or 9, wherein the molar ratio of metal
ions:dithiocarbamate ions is 1:5 to 5:1.
11. The process according to any one of claims 8 to 10, wherein the aqueous solvent is
water or water-based buffer, such as phosphate, citrate, acetate, Tris, HEPES, saline,
glucose solution; preferably, the aqueous solvent is sterile.
12. The molecular complex assembly particulate form according to any one of claims 1 to
7 for use as therapeutic and/or diagnostic agent.
13. The molecular complex assembly particulate form according to any one of claims 1 to
7 for use in a method of therapy selected from chemotherapy, gene therapy and/or immunotherapy
of cancer, radiotherapy or thermotherapy of cancer, tumor treating fields and/or in
a method of imaging of tumors.
14. The molecular complex assembly particulate form for use according to claim 12 or 13,
wherein the complex particle form is administered per-orally, topically or parenterally
and is preferably sterile filtered.
15. The particulate form according to any one of the claims 1 to 7 or for use according
to any one of the claims 12 to 14, wherein is in a dry form, preferably in a lyophilized
form and further comprises at least one cryoprotectant selected from monosaccharides,
disaccharides, amino acids, polysaccharides, polymers and other substances with cryoprotective
properties, and derivatives thereof, in particular selected from mannitol, trehalose,
saccharose, albumin, lactose, dextrose, sucrose, glucose, maltose, inositol, raffinose,
inulin, maltodextrin, heparin, 2-hydroxypropyl-β-cyclodextrin, glycerol, sorbitol,
mercaptans, polyethylene glycol, adonitol, amino acids, polyoxyethylene sorbitan fatty
acid esters, polyoxyethylene-polyoxypropylene copolymer, polyoxyethylene alkyl ethers,
sodium dodecyl sulfate, ascorbic acid, polyvinylpyrrolidone, dextran.